Portable backrest



FIG. 1 is a perspective view of a front side of the portable backrest;

FIG. 2 is a side view showing a first side thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a side view showing a second side thereof;

FIG. 5 is a back view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof;

FIG. 8 is a perspective reduced view of the front side thereof showing the portable backrest mounted on a tree;

FIG. 9 is a perspective view of a front side of an alternative embodiment of the portable backrest;

FIG. 10 is a side view showing a first side thereof;

FIG. 11 is a front view thereof;

FIG. 12 is a side view showing a second side thereof;

FIG. 13 is a back view thereof;

FIG. 14 is a top view thereof; and,

FIG. 15 is a bottom view thereof.

The broken lines in FIG. 8 showing environment are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a portable backrest, as shown and described. 